Mini bows, advantages/disadvantages to short axel length

Completely new to this and I'm looking at the mini compound bows for on a sail boat to hunt anything from pigs and goats to crabs.

I've been looking at the Gearhead Disruptor pro 20 and the Liberty 1, (I'm open to any other suggestions). I'm wondering what the downsides to the shorter axel to axel bows are.

 

Did I ask something stupid ?

 

I only have experience with a helim and then a halon6 so I can talk to it a little.

The shorter you go the lighter you are and more versatile.
But with length and weight come stability and ease of shooting longer distance.
I miss my short bow.

 

Thanks, that sounds more promising than I thought. What would you call a suitable range for goats with a 21" ATA, 70lbs, with a 280fps.

 

As to range, I would test your rig and find what you are accurate to. Practice is key.

 

21" axle to axle, wow, that's short.
A shorter axle to axle is generally more "critical" to shoot. They are more critical to form flaws, and also harder to keep from canting. They have a more extreme string angle which in many cases takes away the ability to get that tip of nose to string contact. This takes away one of your anchor point checks.
I personally prefer to not go any shorter than around 31" axle to axle and have no troubles in a stand.

No one will be able to tell you what your "suitable range" (aka effective range) will be, we all vary too much as do our setups. You will need to test yourself and your equipment to know at what range your groups open up enough that your worst group won't still be in the vitals of whatever animal you're hunting.
To do this you can look up the size of the vitals on the animal you'll be hunting (I know you said speed goats, but I didn't look up their vital size).
For example, if the animal's vital zone is 10" and you hold in the center of that, then a 5" group would be the max spread that you could expect to still be in the vitals. Most like to reduce that a bit more for some breathing room. On an animal with 10" vitals I wouldn't want to see more than a max 4" group size, so I would shoot out to the distance where I found that I couldn't keep all my arrows within a 4" group. Remember to shoot from whatever positions you might possibly shoot from, standing, kneeling, sitting, etc.